My AC guy has proposed two 3 ton systems and I have to choose. The main difference is in the choice of coils. He suggests I buy the same condenser for either coil A or coil B. Whichever coil I choose, he will use a TXV.

Given the use of a TXV, is there really any difference between an evaporator coil's effectiveness? I realize warranty and construction quality are considerations too but my question regards a coil's effectiveness at delivering 3 tons of cooling with a TXV as a metering device and a 3 ton condenser. What might make one coil cool better than another?